1. Field of the Invention
This invention relates to two-stroke-cycle internal-combustion engines having pistons and cylinders larger in diameter at a supercharge section than at a combustion section in order to provide supercharged intake air to a combustion end and an expandable combustion chamber to provide variable compression ratio in working relationship with either various forms of swash-plate or a crankshaft means for converting reciprocative travel of pistons to rotational power output.
2. Description of Related Art
One of the problems with present two-stroke-cycle internal-combustion engines is incomplete scavenging of exhaust gases before intake air enters cylinders for compression. This decreases the amount of unused air available for thorough combustion. Another problem is volumetric inefficiency of compression by not drawing in a full cylindrical volume of air for compression. Another problem applicable to carbureted two-cycle engines is losing fuel mixed with air through exhaust ports in two-cycle scavenging systems. Still another problem is the premixing of fuel with lubricant made necessary by loss of lubricant through exhaust ports if supplied at rings as in four-stroke-cycle engines.
Swash-plates are a form of cam drive. They have been known longer than crankshaft engines and there are more patents on various types of cam-drive engines than on any other type of engine. Swash-plate engines are referred to also as round engines or barrel engines. In physical principle, however, the crankshaft engine also is a cam-drive engine when considering action of a piston against a cylinder wall.
It has long been known that the swash-plate type of cam drive can be more efficient than the crankshaft type of cam drive due largely to cyclical, low leverage of crankshaft drives. Before the advent of turbine engines for aircraft use, considerable research and analysis was done in relation to piston engines for propeller propulsion. Being considered then were various types of swash-plate engines as explained in a paper presented to the Society of Automotive Engineers by E. S. Hall on Mar. 14, 1940. Swash-plate engines were recommended as having greater potential advantages than crankshaft engines, even though there were some problems with swash-plate engines that had not yet been solved. Many problems have been solved for swash-plate and crankshaft engines since then and many mentioned in that paper had already been solved but were not acknowledged.
This invention provides major mechanical and thermodynamic improvements to both swash-plate engines and to crankshaft engines. New and better working relationships of parts are employed for solving the above problems of internal-combustion engine systems.
Variable combustion also has been known since the early days of engines. However, means for achieving variable compression have been complex and so costly that their advantages have not been utilized.
Referring to the cited prior art patent documents, DeLorean employed a swash-plate with a pivotal cam-follower the same as taught by the Shaw patent in 1961 for converting reciprocative travel of pistons to rotational power of an output shaft. This was a major improvement over single-point contact of other swash-plate devices. It made use-life competitive with other drive systems under the high-pressure and impact conditions of combustion in an engine. Previously cam drives had been acceptable for only low-pressure conditions in such mechanisms as the swash-plate compressor for refrigeration and air conditioning currently being used by major car manufacturers. DeLorean also taught linear movement of a cylinder head with a fluid controlled by a ball valve for regulating compression ratio. But that patent did not teach supercharged compression, nor was it possible to achieve supercharge compression with that engine in the efficient manner that is taught by Applicant. In addition, the fluid method for controlling compression ratio was expensively complicated to achieve in conjunction with adequate cooling of the cylinder head for the engine system in which it was employed.
The Williams patent taught regulation of compression ratio in a crankshaft engine by means of a screw-jack device positioned centrally in a plurality of cylinder heads and operable by a common worm shaft. Spark plugs were insertable through a central channel in the screw of the screw jack with an extension wrench. The Williams patent was limited to valve-in-head cylinders typically used for 4-stroke-cycle engines. A device employing geared threading in this invention is positioned outside of a cylinder head in a manner that it is easier to operate, less expensive, does not interfere with placement of spark plugs and does not inhibit cooling of cylinder heads where dissipation of engine heat is most critical.
The Shaw patent taught a pivotal cam-follower for a swash-plate engine. It is referenced here primarily to demonstrate public domain of this particular feature that is employed in the DeLorean patent.
Both of the Holmes patent and the Allison patent are referenced only to demonstrate prior swash-plate art. They do not teach either a supercharge system nor a regulator of compression ratio for a two-stroke combustion cycle as taught by this invention.